1. Field of the Invention
This invention relates generally to agricultural planting equipment, such as air seeders, and, more particularly, to an agricultural product delivery system and method for reducing the speed of an agricultural product such as seed and/or fertilizer entrained in an air stream of the conveying lines of the agricultural product delivery system. Even more particularly, the present invention relates to a cyclone for use with an agricultural product delivery system to eliminate the velocity of product in the air stream of the agricultural product delivery system.
2. Discussion of the Related Art
Conventional planters typically include a series of evenly spaced row planter units connected to an implement frame or tool bar so as to be towed across a field. The row planter units are generally configured to plant particulate product (i.e., seed, herbicide, pesticide, fertilizer, etc.) in evenly spaced individual rows. The planter is usually towed by a propelling vehicle such as a tractor or other prime mover across the field. In many conventional planters, a pneumatic conveying or product delivery system is used to move agricultural product from a supply unit or hopper to the ground. The operating steps typically include, using a plowshare or other furrow opening device to break the ground and cut a furrow, moving the seeds pneumatically into the furrow by means of a conduit located immediately behind the plowshare and then covering the furrow.
Pneumatic agricultural product delivery systems utilize pressurized air to assist in the delivery and movement of particulate material or product such as fertilizer, seed, insecticide or herbicide from a product supply chamber to a growing medium, such as soil. Such pneumatic agricultural particulate material delivery systems are commonly employed in planters, drills and a variety of other agricultural implements. Known pneumatic agricultural product delivery systems typically use pressurized air to move the product through an interior passage provided by a series of elongate tubes which extend from the product supply chamber or hopper to an outlet adjacent to the soil. The series of tubes typically includes an upper flexible hose or tube connected to the product supply chamber and a lower seed tube connected to the upper flexible tube and supported adjacent to the soil. The lower seed tube is typically supported adjacent to a furrow opening disk and includes a funnel-shaped end through which the product flows and is deposited into the newly formed narrow furrow.
Although pneumatic delivery systems enable a more controlled delivery of product to the growing medium, such pneumatic delivery systems are not without problems. For example, in many pneumatic delivery systems, the high velocity of the air stream causes the product to bounce or to be blown out of the furrow. As a result, the accuracy of product placement is reduced and/or extremely difficult to predict or control.
There have been previous attempts at curing the above noted problems. Different forms of retarding or braking devices are known in the industry. For example, some prior art devices utilize a venting system to enable pressurized air to escape as it approaches the soil opener. Other devices both release air and attempt to slow the product velocity with deflectors. For example, some systems include a seed brake wherein a kinked tube having a relatively large air opening on the inner curved side of the tube above the kink is spliced between the upper tube and the lower tube. Despite some improvement in reducing the velocity of the product, none of the prior solutions has provided a fully acceptable solution. Both the prior art venting systems and the deflecting systems do not provide predictable results.
One attempt at providing a solution to the problem of increased seed velocity is described in U.S. Pat. No. 4,493,273 to Gauchet et al. the disclosure of which is hereby incorporated by reference. The system described in the Gauchet patent utilizes a single inlet free floating cyclone. The planting assembly includes a tubular support arm for carrying a plowshare and for conveying seeds pneumatically. The front end of the tubular support arm is connected to a supply of air entrained seeds. The rear end of the tubular support is connected to a cyclone separator for separating the seeds which proceed through a conduit to the furrow cut by the plowshare. While the above described invention was somewhat satisfactory for its intended purpose, the invention exhibits numerous drawbacks. For example, the cyclone is not rigidly mounted to the frame of the planter. As a result, the rugged movement of the planting device across a rough field affects the performance of the cyclone. In addition, due to the cyclone's location, at or near the plowshare, the cyclone is mounted roughly at a 45° angle in relation to the ground. As a result, the full affect of the cyclone cannot be appreciated.
In addition, none of the known prior art systems take into consideration the necessity of planting a mixed product from multiple conveying lines, and effectively eliminating the unwanted spread of the mixed product via a single reducing device. When planting a field it is not uncommon that more than one product stream is directed into the furrow to be planted simultaneously. In many cases, each product is metered into the same delivery line. Unfortunately, these products are seldom applied at the same rate so their speed through the delivery lines are rarely, if ever, the same. As a result, the concentration of particular products in a mixture becomes inconsistent.
Furthermore, none of the prior art systems provide a cyclone that can be used to diffuse air velocity and wherein the air flow and reduction of air pressure can be adjusted. All of the known prior art systems provide a cyclone that cannot be adjusted. This is problematic because higher concentrations or rates typically imply higher transfer velocities and greater air velocities. The prior art non-adjustable cyclones are limited because the same velocity reducing device design does not necessarily function uniformly under these diverse conditions. Therefore it is desirable to have a cyclone which can be adjusted to respond to varying conditions.
Therefore, there is a continuing need for a pneumatic agricultural product delivery system wherein predictable behavior can be achieved to effectively release all air and bring the vertical velocity of the product to zero at some point above the soil opener. There is a an additional need for such a system that can receive multiple conveying lines and be adjusted or controlled to respond to different operating condition. There is a need for such a system that does not require additional parts, which does not require additional space, which minimizes or prevents the escape of particulate material prior to the particulate material reaching the soil, and/or which minimizes the damage caused by the escape of corrosive particulate material.